The present invention relates to a communication system, a communication apparatus, and a transmission controlling method, and more particularly to a technique for determining a transmission method on a reception side.
Techniques such as transmission power control and link adaptation are used in mobile communication in some cases. Those techniques are adopted in order to enhance communication quality as much as possible in those cases of mobile communication where the electric wave propagation environment changes violently.
Patent document 1 discloses a concrete example of transmission power control. As disclosed in patent document 1, it has been common practice for transmission power to be controlled in order to suppress the power consumption in a communication apparatus and reduce the radio wave disturbance on other communication channels while maintaining communication quality.
[Patent document] JP 2002-199437 A
Here, in the above-mentioned conventional method, a reception side communication apparatus transmits information about a line quality situation of a communication which is received thereat to a transmission side communication apparatus. The transmission communication apparatus performs the transmission power control and data rate change control (link adaptation) based on the information about the line quality situation which is received thereat.
However, because of the adoption of such a method, the transmission side communication apparatus must execute processing for calculating a suitable transmission power and processing for selecting suitable data rate based on the line quality situation, and therefore must execute a lot of processing. In particular, a large amount of processing when a mobile station apparatus in mobile communication system becomes the transmission side communication apparatus becomes a serious problem in terms of promotion of low power consumption in the mobile station apparatus.